This R21 application proposes to rigorously examine the mechanisms of behavior change (MOBC in Motivational Interviewing (MI). We will conduct a small pilot study to disaggregate MI into its component parts and test full MI compared to MI without its directive strategies. This test will compare whether the directive elements of MI are critical or whether MI effects may be attributable solely to its Rogerian, non-directive components. Rogerian elements are commonly referred to as MI spirit. We label our treatment conditions Full MI (FMI) and Spirit-Only MI (SOMI). In addition, we will test whether hypothesized main effects of FMI are mediated via increases in commitment to using state-of-the-art assessment methods. We will also examine whether non-specific therapy factors alone significantly reduce drinking when compared to a condition that controls for non-therapy factors. We will test this by comparing outcomes of SOMI to a wait-list control (WTL) that incorporates assessment and encourages self-monitoring and self-change. We will also test whether SOMI's main effects are mediated by increases in mood and greater belief in the ability to change. In addition, we will examine patterns of temporal relationship between mediators and drinking using daily process data in an attempt to address temporal ordering issues. Finally, we will employ, extend, and evaluate a number of new methodologies that hold promise for improving future MOBC research. Our work on MOBC for MI will take place in the context of studying brief treatment for individuals with primary AUD who seek to reduce but not stop drinking. We will recruit 90 individuals with AUD; collect daily process data during a pre-treatment week; and then assess and randomly assign them to 3 conditions: FMI, SOMI, and WTL. Participants will be followed for 9 weeks using daily Interactive Voice Recording (IVR) and in-laboratory assessments at weeks 0, 1, 4 and 8. Those in treatment conditions will receive 4 sessions of treatment at weeks 1, 2, 4, and 8. WTL will receive treatment after completing the 8 week assessment period. Participants in FMI and SOMI will be followed for an additional 4 weeks post-treatment (week 12). We note that, consistent with the purposes of the R21, the aims of this study are exploratory and designed to generate preliminary results. PROJECT NARRATIVE: Motivational Interviewing (MI) is an effective intervention with tremendous implications for a variety of populations suffering from conditions and disorders related to public health, including smoking, gambling, exercise adherence, nutrition, illicit drug use, and alcohol abuse. This R21 grant is a pilot study to investigate the mechanisms of change of MI. If its aims are achieved, it will strengthen the efficacy of MI, which can be utilized and implemented in a variety of health\settings. [unreadable] [unreadable] [unreadable]